The present invention relates to a device for checking containers, in particular preforms.
The device is included in the sector of bottling systems, substantially at the start of the production line.
As is known, plastic bottles for bottling are made by means of several successive processes which include, firstly, the formation of the so-called preforms and, secondly, preform blowing to obtain the finished bottle.
The preforms are cylindrical containers in which the mouth, neck and threaded portion of the neck already have their final dimensions, whilst the bottle body is cylindrical and has substantially the same diameter as the neck. The preforms are then transferred to a blowing machine, in which they are inserted in a mould with the final shape and dimensions of the bottle.
The preforms are formed by moulding with intermittent production, using a mould with a set of cavities arranged in rows. The mould is tilted to unload a row of preforms onto a conveyor which links the forming station and the subsequent blowing station.
The teachings of prior art have some important disadvantages. Firstly, the preforms moulded in rows inside the mould are tipped loose onto the conveyor belt. Then they are set upright again and arranged in a row before entering the blowing station.
This procedure involves the use of intermediate devices between the forming station and the blowing station, which increase production times and complicate plant layout.
Secondly, during the stage in which they are tipped onto the conveyor, the preforms are subject to impacts and damage which may compromise the good condition of the final bottle and, as a result, give rise to rejects which affect the production cycle of the entire plant.
Moreover, in known bottling plant, the preforms are transferred directly from the forming machine to the blowing machine without intermediate checks on the good condition of the preforms and production uniformity.
The aim of the present invention is, therefore, to overcome the above-mentioned disadvantages by providing a device for checking containers, in particular preforms, which picks up the preforms arranged in rows and transfers them to successive stations, in particular to the forming station, avoiding any damage and superfluous transfers and rearrangement of the preforms.
Another aim of the present invention is to provide a device for checking preforms which allows adaptation between the forming station intermittent operation and the continuous operation of the plant downstream of the forming station.
These aims are fulfilled by the device for checking containers, in particular preforms, disclosed whose characteristics are described in the claims herein and, in particular, characterised in that it comprises an infeed and accumulation section for the containers loaded alternately from a forming station, a continuously rotating carrousel and connecting means inserted between the infeed and accumulation section and the carrousel and having means which adjust the alternate operation of the infeed section relative to the continuous operation of the carrousel.